c# - Using updatepanel with gridview templatefield (ImageButton), Firing event but no changes in forntend -

i using updatepanel templatefield itemtemplate imagebutton control. when imagebutton pressed event behind button fired mend populate textfields not do.

.aspx code:

                                          <asp:templatefield showheader="false">                                                 <itemtemplate>                                                     <asp:updatepanel id="updatepanel4" runat="server">                                                         <triggers>                                                             <asp:asyncpostbacktrigger controlid="_btnuseredit" eventname="click" />                                                         </triggers>                                                         <contenttemplate>                                                             <asp:imagebutton id="_btnuseredit" runat="server" imageurl="~/images/edit.png" commandname="" height="30px" width="30px" onclick="_btnuseredit_click" causesvalidation="false" />                                                         </contenttemplate>                                                     </asp:updatepanel>                                                                                                     </itemtemplate>                                                 <itemstyle width="35px" />                                             </asp:templatefield> 

c# code:

protected void _btnuseredit_click(object sender, eventargs e)     {         using (establishmentdatacontext db = new establishmentdatacontext())         {             imagebutton btn = (imagebutton)sender;              gridviewrow row = (gridviewrow)btn.namingcontainer;              id = convert.toint32(row.cells[0].text);              var edit = (from in db.users a.userid == convert.toint32(row.cells[0].text) select a).firstordefault();              _txtname.text = edit.name;             _email.text = edit.useremail;             _password.text = _txtconfpassword.text = edit.strpassword;         }     } 

for using asyncpostbacktrigger inside gridview need add trigger in rowdatabound event this.

protected void gridview1_rowdatabound(object sender, gridviewroweventargs e) {     if(e.row.rowtype == datacontrolrowtype.datarow)     {         var editbutton = e.row.findcontrol("_btnuseredit") imagebutton;         updatepanel1.triggers.add(new  asyncpostbacktrigger{               controlid=editbutton.uniqueid,              eventname="click"});     } }